This patent relates to the field of tubing and tubing connectors. Metal tubing is widely used for the supply of liquids and gases under high pressures and temperatures. Sections of such tubing are connected by fittings which must fasten together straight sections of tubing, by providing a joint which withstands mechanical separation forces and which does not leak.
The such joints are typically formed by mounting separate threaded connectors to the tubing ends. These separate connectors are slid over the tubing section ends and permit the tubing ends to be fastened together by interlocking corresponding connectors. Such connections are referred to herein as two piece connectors. Securing the connectors to the tubing ends forms the basis of the mechanical interconnection. In the prior art, such connections are usually formed by either flaring the tube so that the connector bears on the tube, applying sufficient force to hold the tubing ends in tight connection, or a relatively soft metal collar is deformed by the connector against the outer wall of the tubing to form both a seal against leaks and a means for the connector to grip the tube to exert forces against the tendency of the tubing joint to come apart.